Intermap Technologies Inc.20060203"hopd5nwmb.bil"1Digital Elevation ModelDigital Terrain ModelsVersion 1Englewood, COIntermap Technologies Inc.<URL:http://www.intermap.com><URL:http://www.intermap.com/images/handbook/producthandbook.pdf>
This data set is a digital elevation model (DEM). The DEM products are generated
using the Intermap STAR-3i(Reg.) airborne interferometric synthetic aperture
radar (SAR) system mounted in a LearJet 36A aircraft.
The Modified Digital Terrain Model (MDTM) data files are digital representations of cartographic
information in a grid form after the application of Intermap's proprietary system known
as TerrainFit(Reg.) and a subsequent filtering process. TerrainFit(Reg.) removes high frequency variations
found in the first reflective surface DEM. This effectively removes elevation posts
of features such as manmade structures, isolated trees, etcetera that have a relatively
small footprint. Having removed these features the final regular posted DTM is derived
through interpolation of the remaining elevation posts.
The filtering process is designed to reduce the noise level in the data.
The DTM data for 7.5-minute by 18-minute units correspond to the USGS
1:63,360 scale topographic quadrangle map series for available areas in the United States.
Each 7.5-minute by 18-minute DTM is based
on 5m postings using the Universal Transverse Mercator (UTM) projection.
Each 7.5-minute by 18-minute tile provides full coverage with overlap into adjacent
tiles.
The DTMs are used as a fundamental layer of information in Geographic
Information Systems (GIS) and Spatial Information Decision Support Systems
(DSS). A number of the priority layers of spatial information recognized
by the National Spatial Data Infrastructure may be derived from Intermap
DEMs, including elevation, hydrography, slope, aspect, and shoreline
delineation.
The STAR-3i(Reg.) system employs three principal technologies: X-band Horizontal
-Horizontal (HH) polarized SAR, a ring laser-based inertial measurement unit
(IMU), and Differential Global Positioning System (DGPS). STAR-3i(Reg.) was developed
by the Environmental Research Institute of Michigan (ERIM) under contract to
the U.S. Defense Advanced Research Projects Agency (DARPA).
The system is comprised of two X-band radar antennae that collect data
simultaneously. The set of acquired data are "interfered" by a digital
correlation process to extract terrain height data and geometrically
correct radar images. STAR-3i(Reg.) uses post-processed DGPS data, together with
precise inertial measurement data, to attain highly accurate positioning
control. Precise terrain height and positioning data are enhanced by
careful calibration of the baseline separating the two antennae.
The STAR-3i(Reg.) system accuracy has been independently validated by tests
conducted by the U.S. Army Topographic Engineering Center, the Institute
of Navigation, Stuttgart University and by NASA. A summary of test results
are accessible at <URL:http://www.intermap.com>.
2005062120050624
The above dates refer to the time of field data acquisition and therefore reflect
ground conditions at that time.
CompleteOngoing-159.04866128478668-158.6494958253039769.00616757804964268.868782290224530MEL_Scientific-Engineering_Field_ThesaurusElevationCartographyGeodesyGeographyHypsographyMappingPhotogrammetryStereophotogrammetryTopographyRadarInterferometricRemoteSensingSARDEMDTMDSMORRIORISTAR-3i(Reg.)INSARIFSARIFSAREGEOSARheightNoneUSAAlaskaNationalPetroleumReserveMEL_Environmental_Domain_ThesaurusTerrainEarthSurfaceBaldGroundFirstNone2005JunePurchaseNoneIntermap Technologies Inc.Data Archive Managermailing address400 Inverness Drive S., Suite 330EnglewoodCO80112-5847USA(303) 708-0955(303) 708-0952mailto:info@intermap.com
This data was produced by Intermap Technologies Inc.
This data is delivered on interoperable media with metadata
and a quality control report. The data set was developed on Intel Xeon processors
running Microsoft Windows 2000 Server Operating System.
Calculation of the digital elevation model accuracy is described in the Product
Handbook User's Guide. <URL:http://www.intermap.com/images/handbook/producthandbook.pdf>
<URL:hopd5nwcx.pdf>
Coverage maps are provided for each area of acquisition.
<URL:http://www.intermap.com>
This data is derived from a DSM of an accuracy of 2.5 meters RMSE or better in areas of
unobstructed flat ground. This accuracy is no longer guaranteed due to the filtering procedures.
This data derived from a DSM of an accuracy of 1 meter RMSE or better in areas of unobstructed flat ground. This accuracy is no longer guaranteed due to the filtering procedures.
This DEM data product was derived using Intermap Technologies' STAR-3i(Reg.) airborne
interferometric SAR data acquisition system. The flying height is
29,500 feet Above Sea Level. The primary look direction is North.
Areas of missing data are interpolated using
continuous curvature spline over non-data areas. The phase unwrapper utilized is IfprocT.
Most incidences of non-data areas are due to radar shadow and layover due to steep terrain.
Radar shadow is a factor of the local topography. It is often found in mountainous regions
and the urban canyons of built-up areas. Occurances of non-data areas within a DEM are dependent
on the look direction of the radar. Significant bodies of water are assigned an elevation
which corresponds to the shoreline. Areas of null data are assigned the value -32767.
This data was derived from the original DSM through the application of the TerrainFit(Reg.) bare earth
processing system and the subsequent application of a 3X3 median filter run with four iterations. The
intent in processing the DSM this way was to reduce the inherent variability within the DSM so that
contours generated at a one meter interval would conform to standard cartographic expectations. This
is an artificially smoothed DSM that was derived from data with a horizontal positional
accuracy of 2.5m RMSE and a vertical positional accuracy of 1m RMSE. These
accuracies can no longer be guaranteed given the filtering procedures.
20060203RasterGrid Cell30563192Universal Transverse Mercator40.9996159 degrees West0500000.0 meters0.0 meterscoordinate pair5.05.0MetersNAD83GRS806378137298.257222101NAVD88-Geoid990.01 mmeterImplicit coordinate5 meter posting grid cell
The DEM is a 32 bit IEEE floating point value Big Endian organized
in a one-channel binary interleaved file (BIL) on a 7.5-minute by 18.0-minute
geographic (lat/long) grid in UTM projection. The origin of the
post is center center.
<URL:http://www.intermap.com/images/handbook/producthandbook.pdf>Elevation value per grid cell.Height of the geoid, relative to mean sea level.<URL:http://www.intermap.com/images/handbook/producthandbook.pdf>392.5632.631meters0.01 m or better
>Project Information
>NPRA5 Task Order#: 01014C0058
>Project Area: Alaska National Petroleum Reserve
>Intermap Project Number: 05006
>Time of Collection
>Flight Segment: m446p10s2
>Base Stations: NPRA5BK1-NPRA5BK2
>Flight Direction: 90
>Pass Acquisition Start Time (includes GPS week): 415521.9948
>Pass Acquisition Start Time (GPS in HH:MM:SS): 19:25:21
>Pass Acquisition Start Time (UTC in HH:MM:SS): 19:25:08
>Pass Acquisition End Time (includes GPS week): 416265.4735
>Pass Acquisition End Time (GPS in HH:MM:SS): 19:37:45
>Pass Acquisition End Time (UTC in HH:MM:SS): 19:37:32
>Pass Acquisition Date: 23-Jun-05
>Flight Segment: m446p1s2
>Base Stations: NPRA5BK1-NPRA5BK2
>Flight Direction: 270
>Pass Acquisition Start Time (includes GPS week): 343952.8234
>Pass Acquisition Start Time (GPS in HH:MM:SS): 23:32:32
>Pass Acquisition Start Time (UTC in HH:MM:SS): 23:32:19
>Pass Acquisition End Time (includes GPS week): 344684.6386
>Pass Acquisition End Time (GPS in HH:MM:SS): 23:44:44
>Pass Acquisition End Time (UTC in HH:MM:SS): 23:44:31
>Pass Acquisition Date: 22-Jun-05
>Flight Segment: m446p2s2
>Base Stations: NPRA5BK1-NPRA5BK2
>Flight Direction: 90
>Pass Acquisition Start Time (includes GPS week): 345635.6755
>Pass Acquisition Start Time (GPS in HH:MM:SS): 0:00:35
>Pass Acquisition Start Time (UTC in HH:MM:SS): 0:00:22
>Pass Acquisition End Time (includes GPS week): 346326.4709
>Pass Acquisition End Time (GPS in HH:MM:SS): 0:12:06
>Pass Acquisition End Time (UTC in HH:MM:SS): 0:11:53
>Pass Acquisition Date: 23-Jun-05
>Intermap Processing AML Version: 1.1.3, 20031104
>ISO 9001 Certification No.: A8379
>DEM Origin (North West Corner)
>UTM_Easting_(meters): 498057.5
>UTM_Northing_(meters): 7655047.5
>DEM Extents
>UTM_Easting_(meters): Min. 498055 Max. 514015
>UTM_Northing_(meters): Min. 7639770 Max. 7655050
<URL:http://www.intermap.com/images/handbook/producthandbook.pdf>
20060404Intermap Technologies Inc.Data Archive Managermailing address400 Inverness Drive S., Suite 330EnglewoodCO80112-5847USA(303) 708-0955(303) 708-0952mailto:info@intermap.comFGDC Content Standards for Digital Geospatial MetadataFGDC-STD-001-1998